Microstructured valves are described in EP-A1 208 386. In the known valve arrangement a flow path distributor in the shape of an essentially plane silicium disc has appropriate elevations and fluid paths with respective openings; which can be opened or closed by means of a movable membrane used as actuation element. The membrane serves as the actuation element and it is provided with a piezoelectric material, thus it can be moved by applying a voltage. In order to open one of the fluid paths, the piezoelectric membrane has to be lifted against a spring working in the closing direction. The expansion caused by the change in length of the piezoelectric material generates the necessary opening force, energy being used during the transition from the closed to the open position. In the open position, the voltage at the piezoelectric membrane has merely to be maintained to keep it open. Now the actuating drive serves as a holding device and does not have to generate energy except for the minor holding energy. If the fluid path is to be closed again, is sufficient to switch off the holding voltage, so that the membrane follows the force of the spring and is moved back into its closing position.
In the known valve arrangement it is a disadvantage that the piezoelectric element can be overcome or hold strong forces, but that the regulating distances can only be executed in limited measures and reverse. As changes in the length by means of piezoelectric ceramics and the simultaneous development of strong force can only be effected in the per mil range, an extension of the distance has for example to be effected by means of a lever transfer apparatus. Herein, however, the transferrable force is decreased correspondingly. Strong fluid flows with correspondingly high pressure can therefore not be switched with the known valve arrangement.